| 摘要 |
PURPOSE:To prevent an erroneous detection by regarding as the malfunction of an inspection signal generator when a plurality of filter malfunctions are detected by one inspection. CONSTITUTION:In order to inspect the filters 2a-2c of a current signal input circuit, input circuits 8a-8c are switched by an inspection command issued from a CPU to input a signal from an inspection signal generator 9. The outputs of the filters 2a-2c are input to a multiplexer 5, and input through an A/D converter 6 to the CPU 7. The CPU 7 checks the signal values and outputs malfunction signals fa-fc if they malfunction. When any two or more of the signals fa-fc simultaneously become ON, the output of a circuit NOR 1 shows '0' level, and AND gates AND 4-AND 6 are blocked; then the signals fa-fc are not externally output. |
